Probation officers are authorized to detain persons found in a juvenile probationer’s house to monitor the probationer’s compliance with the terms of his probation. In July 2007, Probation Officer Morris, along with other probation officers, went to juvenile probationer R.R.’s residence. Morris knew that R.R.’s probation prohibited him from associating with gang members and allowed searches. When Morris entered the house he encountered Rios, who refused to identify himself. Based on Rios’ evasiveness, appearance, and behavior, Morris believed he was gang-associated and was trying to hide a weapon. When Rios refused to stand and be frisked, Morris and another officer took Rios to the ground and handcuffed him. A gun fell out of Rios’ shirt; he also had a switchblade. As Rios failed to contest the lawfulness of the officers’ entry at trial, his belated effort to do so on appeal was rejected and the issue was limited to the lawfulness of Rios’ detention. The court found that Rios was legitimately on the premises, but was no more than a casual visitor. As such, he failed to establish that his Fourth Amendment rights were violated by a search of the residence. With respect to the seizure of his person, officers were authorized to detain him incident to the search of R.R.’s home. They knew R.R. was prohibited from associating with gang members, and Rios had what appeared to be gang tattoos. Thus, the officers were authorized to detain Rios to ascertain his identity and relationship to the probationer and the residence. His search was justified by Morris’ belief that Rios might be armed. Appellant’s contention that the prosecution was required to prove the scope and precise terms of the juvenile’s probation conditions (i.e., including R.R.’s residence), was rejected. First, this issue was not raised below. Further, trial counsel’s failure to do so was not ineffective assistance of counsel. Officer Morris testified the court had imposed “every term and condition possible” on R.R., which is inconsistent with a search term being limited to R.R.’s person. Finally, Morris’ status as a probation officer did not limit his authority to detain Rios because he was acting within the scope of Welfare and Institutions Code section 830.5, subdivision (a)(1) in supervising R.R.’s probation.