## Facts

- Police used a peer-to-peer investigation tool and identified an IP address that was sharing files believed to contain child pornography.
- An officer downloaded four video files from that IP address; the files contained child pornography.
- An administrative subpoena to the Internet service provider linked the IP address, at the relevant date and time, to a subscriber name (Angel Martinez) and to a specific Massachusetts apartment address in a public housing development.
- Additional inquiry showed the apartment leaseholder was Maria Avilez; police did not confirm that the subscriber resided at the apartment.
- Police obtained a warrant to search the apartment for computers and digital devices connected to child pornography offenses, based on the IP address activity and ISP assignment records.
- During execution of the warrant, officers seized two laptops belonging to Adalberto Martinez; forensic review found multiple child-pornography videos.
- Martinez moved to suppress, arguing the affidavit lacked probable cause because police had not verified the subscriber lived at the address, had not linked him to the apartment pre-search, and had not investigated whether the Internet connection was wireless or unsecured.
- The trial judge denied suppression; after a jury-waived trial, Martinez was convicted of possession of child pornography.

## Issues

1. Whether a warrant affidavit establishes probable cause to search a residence when it links child-pornography sharing to an IP address and ties that IP address to the residence through ISP assignment records at the relevant time.
2. Whether probable cause is defeated because police did not confirm the named subscriber lived at the residence or connect the defendant to the premises before the search.
3. Whether police must investigate the existence or security of a wireless network to establish a sufficient nexus between suspected online activity and the place to be searched under art. 14 and the Fourth Amendment.

## Decision

- The Supreme Judicial Court affirmed the denial of the motion to suppress and affirmed the conviction.
- The court held the affidavit established probable cause to search the apartment because ISP records tied the offending IP address to that address at the relevant time.
- The court rejected the claim that probable cause required pre-search proof of who used the connection or that the named subscriber actually lived at the apartment.
- The court rejected the claim that police were required to investigate whether a wireless router existed or was unsecured before seeking a warrant.

## Legal Principles

- Probable cause requires a fair probability that evidence of a crime will be found in the place to be searched; it does not require certainty or exclusion of alternative explanations.
- For online crimes, a magistrate may infer a nexus to a residence where an IP address used for illegal file sharing is shown by ISP records to have been assigned to that residence at the relevant time.
- Probable cause to search a location does not depend on probable cause to identify the specific person who committed the offense before the search.
- Generalized possibilities that an unsecured wireless network could be used by a third party do not, without case-specific facts, negate probable cause or impose a duty to perform additional investigation as a prerequisite to a warrant.
- Warrant affidavits are evaluated as a whole in a commonsense manner under both art. 14 and the Fourth Amendment.

## Conclusion

The court upheld a residential search warrant supported by evidence that child pornography was shared from an IP address assigned by ISP records to the target apartment at the relevant time, holding that neither uncertainty about the user’s identity nor speculative unsecured Wi-Fi access defeated probable cause.


Commonwealth v. Martinez, 476 Mass. 410, 71 N.E.3d 105 (2017)