Salvatore Cordileone, the Roman Catholic archbishop-elect of San Francisco, was arrested on suspicion of driving under the influence.

According to the AP, Cordileone was taken into custody after being stopped early Saturday, August 27 in San Diego.

The 56-year-old Cordileone apologized for his “error in judgment” in a statement released Monday.

Pope Benedict XVI named Cordileone, who has served as Bishop of Oakland since 2009, for the job as archbishop last month, and he is set to assume the position in October.

Cordileone played an instrumental role in passage of Proposition 8, California's gay marriage ban.

In 2008, Cordileone, then bishop of San Diego, reached out to help raise $1.5 million to get the measure on the ballot. He organized leading evangelical Christian leaders, such as the Rev. Jim Garlow of Skyline Church, to back the amendment. And he also donated $6,000 of his own money to the campaign.

After passage of the gay ban, he told a Catholic radio show that “the ultimate attack of the Evil One is the attack on marriage.”

The AP quoted canon law experts as saying that Cordileone's arrest probably won't delay his appointment.

(Relate: Pope Benedict elevates anti-gay marriage Timothy Dolan to Cardinal.)