Mauricio Elias Martinez and Juan Ramon Velasquez, both 19, are charged with attempted murder, assault and firearms charges in the July 2 shooting at two men on a San Bruno street. According to prosecutors, Martinez and Velasquez attacked the men who denied any gang involvement and tried to leave. As they walked away, Velasquez fired a handgun four times, striking one victim in the back, according to police reports.

On Thursday, the two men were ordered to stand trial after a third day of preliminary hearings on the evidence, according to court records clerks. Meanwhile, Martinez and Velasquez remain in custody on no-bail status.

The defendants, according to authorities, are members of Mara Salvatrucha, also known as MS-13, M18 or MS. The gangs originated in Central America and spread during the 1980s among Salvadorian immigrants in Southern California, according to reports by gang experts.

They are violent, even by most gang standards, with links to explosives, drugs and murders. News reports nationwide cite machete attacks as a particularly harsh gang method.

The gang continues to have a large presence in El Salvador because deported members tend to recruit more who in turn immigrate illegally back to the United States, immigration officials reported.

In August, federal immigration agents arrested 1,057 gang members, more than half of which belong to MS13.  In September, a two-day sting led to the arrest of nearly 660 members, according to reports.

The recently established Gang Intelligence and Investigations Unit is currently compiling a database on county gang activity and affiliation. Authorities believe the gang is expanding into Northern California but the arrests of Martinez and Velasquez are among the few documented cases in San Mateo County.

Michelle Durand can be reached by e-mail: michelle@smdailyjournal.com or by phone: (650) 344-5200 ext. 102. What do you think of this story? Send a letter to the editor: letters@smdailyjournal.com.